Method of more quickly calibrating display panels and calibration apparatus for performing the same

ABSTRACT

A method of reducing a total, per device, measurements taking time in a calibration system that uses a sensor array that serially reports out its readings and a data processing unit that needs to receive the reported out readings in good order before allowing an under-measurement first display device to advance away from a measurements taking station includes the step of not driving the first display device with all of required full screen test images where each is a full screen display of only a respective one of a predetermined minimum number of grayscale values produced as a minimum number of needed full screen sample images and; in place of at least a first plurality of the not-produced full screen images, driving the under-measurement first display device with a partial screen multi-pattern that presents a plurality of different grayscale values including ones not presented by those of all of the full screen test images that are used to drive the under-measurement first display device. The serially reported out readings from the sensor array for the partial screen multi-pattern and for the full screen test images are obtained and used to generate virtual full screen sample images based on the obtained partial screen multi-pattern and for the full screen test images.

PRIORITY STATEMENT

This application claims priority under 35 U.S.C. §119 to Korean PatentApplication No. 10-2014-0000705, filed on Jan. 3, 2014 in the KoreanIntellectual Property Office KIPO, the contents of which application areherein incorporated by reference in their entireties.

BACKGROUND

1. Field

The present disclosure of inventive concept(s) relates to a method ofcalibrating a plurality of display panels on a mass production basis, amethod of mass producing calibrated ones of such display panels, and acalibration apparatus for performing the methods. More particularly,exemplary embodiments in accordance with the present inventiveconcept(s) relate to a method of calibrating each of a plurality of massproduced display panels while substantially decreasing an amount of timeconsumed for taking measurements for each individual one of the massproduced display panels while still achieving a desired degree ofaccurate calibration and to a calibration apparatus for performing thefaster measurement takings.

2. Description of Related Technology

Generally, a liquid crystal display (“LCD”) apparatus includes a firstsubstrate including a plurality of pixel electrodes, a spaced apartsecond substrate which often includes a common electrode providedthereon and color filters corresponding to primary colors, where aliquid crystal layer is disposed between the first and secondsubstrates. The primary colors may be mixed to produce a desired white(having a respective optical “temperature”). In the LCD, an electricfield is generated by voltages applied to the pixel electrode and thecommon electrode. By adjusting an intensity of the electric field, atransmittance of a light passing through the liquid crystal layer foreach primary color may be adjusted so that a desired color image may beformed and displayed.

The LCD display apparatus includes display control circuitry forcontrolling it so as to display an image corresponding to input imagedata. To improve reliability of the correspondence between the displayedimage and the input image data, typically the whole of the display panelis calibrated by programming it with one or more gamma values and one ormore color coordinate mapping values (gamut mappings). For sake ofaccuracy; it may be desirable to perform gamma calibration and gamutmapping for each of all the possible grayscale values (for example0-255) and for each subarea of the whole display area (DA) so as tothereby produce a uniformly consistent image for all possible grayscalevalues and across the whole of the display area of the displayapparatus.

More specifically, the gamma value(s) and the color coordinatere-mapping value(s) assigned to each individual display panel may beused to compensate for variations among mass produced displayapparatuses coming down an assembly line. The appropriate gamma valuesand color coordinate values may be extracted for example, by takingmeasurements at all sub-areas of the full display area (DA) by using allthe possible grayscales for each such sub-area. However, this can be tootime consuming. For example, when the input image data can have amaximum of 256 different grayscales (GS=0-255) and each measurementstaking (e.g., exposure to a measurements taking camera) consumes afinite amount of time, the total time for merely measuring each of theplural display panels in a mass produced steam of such panels can bequite considerable. Subsampling has been proposed to reduce the perpanel measurements taking time. Under one subsampling approach, thenumber of measurements taking exposures has been reduced, but to no lessthan 10% of the maximum. More specifically, gamma values and colorcoordinate values of 25 different grayscales are taken on a fullscreen-per-grayscale bases and then interpolation is used forcalibrating the gamma values and the color coordinate re-mappings of all256 of different grayscales of the display panel.

However, even when snapshot images of 25 sample and full screengrayscales are taken under the 10% subsampling approach and while usingan appropriate camera apparatus, a time duration of about 200 ms may beneeded for the full screen camera exposure for each one sample grayscaleimage and an additional 300 ms is needed for serially transmitting themeasured data to an appropriate data processing means, where the data isfirst tested for integrity before the next display panel on the assemblyline is allowed to come in front of the camera. Therefore, a minimumtime of about 500 ms may be needed for each full screen snapshot and atotal time of about 12.5 s (seconds) may be needed for taking thecalibration measurements of each single display panel in a mass producedstream of such display panels so that appropriate gamma values and thecolor coordinate re-mappings values may be programmed into each. Thiscan disadvantageously slow production and increase manufacturing costs.(In a variation, the amount of desired exposure time may vary as afunction of the grayscale under measurement, with the darker or lowergrayscale values (e.g., closer to GS=0) calling for longer exposuredurations and the brighter or higher valued grayscales (e.g., closer toGS=255) calling for comparatively shorter exposure durations.)

As explained above, quite a lot of time may be needed for measurementstaking steps during the calibrating of the gamma values and of the colorcoordinate re-mapping values of each of mass produced display panels. Inaddition, when all of the display panels of a mass production batch arenot individually calibrated due to limits on time availability, the,reliability of the luminance and color balance characteristics of thedisplay panels produced from the batch may decrease. In order for themanufacturer to maintain a reputation of excellent reliability for eachdisplay panel in a batch of mass produced and sold display panels, it isdesirable that every display panel be individually tested and calibratedrather than relying on batch statistics and hoping that sporadic testingis good enough. On the other hand, it is also desirable for the cost ofproducing a batch of individually calibrated display panels to be low sothat the manufacturer can pass at least part of the cost saving toconsumers. The problem is how to achieve both of reduced measurementstaking/gathering time and of obtaining a sufficient number of samples ina subsampling process.

It is to be understood that this background of the technology section isintended to provide useful background for understanding the heredisclosed technology and as such, the technology background section mayinclude ideas, concepts or recognitions that were not part of what wasknown or appreciated by those skilled in the pertinent art prior tocorresponding invention dates of subject matter disclosed herein.

SUMMARY

The present disclosure of inventive concept(s) provides a method ofcalibrating display panel where the method is capable of decreasing ameasurements taking time used for generating calibration factors for thedisplay panel.

Exemplary embodiments of the present inventive concept(s) also include amethod of driving a display panel including the method of compensatingfor partial screen images produced on the display panel.

Exemplary embodiments of the present inventive concept also provide adisplay apparatus for performing the method of driving the displaypanel.

In an exemplary embodiment of a method of calibrating the display panelaccording to the present inventive concept(s), the method includesmeasuring luminance and color attribute of a plurality of full screengrayscale images, the full screen grayscale images, measuring luminanceand color attribute of a multi pattern image, the multi pattern imageincluding a plurality of multi grayscales. The method may furtherinclude generating a first compensating value accounting for changing aposition of a multi grayscale region in the multi pattern image from anoff center position to a central portion of the multi pattern image andcompensating luminance and color attribute of the display panel based onthe luminance and the color measurement takings obtained from the fullscreen images and from the multi pattern image.

In an exemplary embodiment, a first compensating value for producingvirtualized full screen images may be generated using a high full imageand a low full image, the high full image having a high full grayscalewhich is one of the full grayscales greater than the multi grayscale andadjacent to the multi grayscale, the low full image having a low fullgrayscale which is one of the full grayscales less than the multigrayscale and adjacent to the multi grayscale.

In an exemplary embodiment, the generating the first compensating valuemay include determining a first difference between a measured value ofthe high full grayscale at a first position and a measured value of thehigh full grayscale at a second position in the high full image and asecond difference between a measured value of the low full grayscale atthe first position and a measured value of the low full grayscale at thesecond position in the low full image, the first position being acentral portion of the multi pattern image, the second position beingthe position of the multi grayscale region and linearly interpolatingthe first difference and the second difference using the high fullgrayscale, the multi grayscale and the low full grayscale.

In an exemplary embodiment, the multi pattern image may include a commonmulti grayscale which is substantially the same as one of the fullgrayscales.

In an exemplary embodiment, the method may further include generating asecond compensating value using a ratio between a measured value of thefull grayscale which is substantially the same as the common multigrayscale and a measured value of the common multi grayscale in themulti pattern image.

In an exemplary embodiment, a measured position of the measured value ofthe full grayscale which is substantially the same as the common multigrayscale may be substantially the same as a measured position of themeasured value of the common multi grayscale in the multi pattern image.

In an exemplary embodiment, the number of the full pattern images may begreater than or equal to three.

In an exemplary embodiment, the number of the multi pattern images maybe two. A first multi pattern image among the multi pattern images maycorrespond to relatively low grayscales and a second multi pattern imageamong the multi pattern images may correspond to relatively highgrayscales.

In an exemplary embodiment of a method of driving a display panelaccording to the present inventive concept, the method includesmeasuring luminance and color of a plurality of full pattern images, thefull pattern image including a single full grayscale, measuringluminance and color of a multi pattern image, the multi pattern imageincluding a plurality of multi grayscales, generating a firstcompensating value to displace a position of a multi grayscale region inthe multi pattern image to a central portion of the multi pattern image,compensating luminance and color of input image data based on the inputimage data, the luminance and the color of the full pattern image, theluminance and the color of the multi pattern image and the firstcompensating value to generate a data signal and displaying an image onthe display panel based on the data signal.

In an exemplary embodiment, the first compensating value may begenerated using a high full image and a low full image, the high fullimage having a high full grayscale which is one of the full grayscalesgreater than the multi grayscale and adjacent to the multi grayscale,the low full image having a low full grayscale which is one of the fullgrayscales less than the multi grayscale and adjacent to the multigrayscale.

In an exemplary embodiment, the multi pattern image may include a commonmulti grayscale which is substantially the same as one of the fullgrayscales.

In an exemplary embodiment, the method may further include generating asecond compensating value using a ratio between a measured value of thefull grayscale which is substantially the same as the common multigrayscale and a measured value of the common multi grayscale in themulti pattern image.

In an exemplary embodiment, the number of the full pattern images may begreater than or equal to three.

In an exemplary embodiment of a display apparatus according to thepresent inventive concept, the display apparatus includes a timingcontroller, a data driver and a display panel. The timing controller isconfigured to compensate luminance and color of input image data togenerate a data signal based on the input image data, luminance andcolor of a plurality of full pattern images, luminance and color of amulti pattern image and a first compensating value to displace aposition of a multi grayscale region in the multi pattern image to acentral portion of the multi pattern image, the full pattern imageincluding a single full grayscale, the multi pattern image including aplurality of multi grayscales. The data driver is configured to convertthe data signal into a data voltage having an analog type. The displaypanel is configured to display an image based on the data voltage.

In an exemplary embodiment, the first compensating value may begenerated using a high full image and a low full image, the high fullimage having a high full grayscale which is one of the full grayscalesgreater than the multi grayscale and adjacent to the multi grayscale,the low full image having a low full grayscale which is one of the fullgrayscales less than the multi grayscale and adjacent to the multigrayscale.

In an exemplary embodiment, the multi pattern image may include a commonmulti grayscale which is substantially the same as one of the fullgrayscales.

In an exemplary embodiment, the timing controller may be furtherconfigured to generate a second compensating value using a ratio betweena measured value of the full grayscale which is substantially the sameas the common multi grayscale and a measured value of the common multigrayscale in the multi pattern image.

In an exemplary embodiment, the number of the full pattern images may begreater than or equal to three.

According to the method of compensating the image of the display panel,the method of driving the display panel including the method ofcompensating the image of the display panel and the display apparatusfor performing the method of driving the display panel, time forcompensating the image of the display panel. In addition, an error dueto a use of multi-patterned image is compensated so that accuracy ofcompensating the gamma value and the color coordinate of the image maybe improved. Thus, the gamma values and the color coordinates may becompensated for all of the display panels so that reliability of thedisplay apparatus may be improved.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features and advantages of the present disclosure ofinventive concept(s) will become more apparent by describing in detailedexemplary embodiments thereof with reference to the accompanyingdrawings, in which:

FIG. 1 is a block diagram illustrating a measurements taking portion ofa mass production display calibrating system according to an exemplaryembodiment in accordance with the present disclosure;

FIG. 2 is a flowchart illustrating a method of measurements taking andcalibrating of a display panel of FIG. 1;

FIGS. 3A to 3C are plan views illustrating full patterns forcompensating the image of the display panel of FIG. 1;

FIG. 3D is a plan view illustrating a multi pattern for compensating theimage of the display panel of FIG. 1;

FIGS. 4A to 4C are conceptual diagram illustrating a first imagecompensation step of FIG. 2;

FIGS. 5A and 5B are conceptual diagram illustrating a second imagecompensation step of FIG. 2;

FIG. 6A is a graph illustrating a gamma value by the image compensationof the display panel of FIG. 1;

FIG. 6B is a graph illustrating a color coordinate by the imagecompensation of the display panel of FIG. 1; and

FIG. 7 is a block diagram illustrating a display apparatus forperforming a method of driving the display panel including the method ofcompensating the image of FIG. 2.

DETAILED DESCRIPTION

Hereinafter, the present disclosure of inventive concept(s) will beexplained in detail with reference to the accompanying drawings.

FIG. 1 is a block diagram illustrating a measurements taking and displaycalibrating system configured in accordance with an exemplary embodimentof the present disclosure for calibrating a stream of mass produceddisplay panels. FIG. 2 is a flowchart illustrating a method ofperforming compensation (including measurements taking) for the displaypanel of FIG. 1. FIGS. 3A to 3C are plan views illustrating so-called,“full” screen gray drive patterns (GF's) used for generatingcompensation parameters based on the images produced by the displaypanel of FIG. 1 and captured and reported by the camera apparatus. FIG.3D is a plan view illustrating a so-called, “multi” pattern (GM) usedfor generating compensation parameters based on the image of the displaypanel of FIG. 1.

Referring to FIG. 1, the system includes an assembly line 990 a-990 bthat sequentially supplies, mass produced display devices 999, 1000,1001, etc. to a luminance and color measuring part 600 (a.k.a. camera600 having an internal sensor array), where the display device (e.g.,1000) posing in front of the camera 600 has an exposure thereof takenand where the results of the exposure (a.k.a. measurements taking) arethen reported to a controlling data processing unit (e.g., computer) 700by way of a serial communications link (e.g., from a serially scannedsensor array (e.g., CCD array, not shown) within the camera 600). Thedata processing unit 700 controls the drivings of the measuring part 600(e.g., starting/stopping of exposure duration for example by controllingan electrically actuated shutter, controlling an electrically actuatedaperture window, defining address ranges of the sensor array that are toreport out their latest readings) and of the being-exposed displayapparatus (e.g., 1000) and collects measurement signals produced andtransmitted thereto by the measuring part 600. Part of the measurementsignals collecting process is that of verifying that all the desiredmeasurement signals have been received and are not corrupted, forexample by noise. Therefore, the being-exposed display apparatus (e.g.,1000) is not released for away-conveyance by a downstream part 900 b(e.g., robotic arm) of the assembly line until all the desiredmeasurement signals are verified as having been received in good orderby the data processing unit 700. And only thereafter is the next in lineand to-be-tested display apparatus (e.g., 1001) conveyed into positionby an upstream part 900 a (e.g., robotic arm) of the assembly line sothat this next in line display apparatus (e.g., 1001) can have itspictures taken by the camera 600.

After being calibrated, each display apparatus (e.g., 999, 1000, 1001,etc.) displays an image based on input image data and on setcompensation parameters (e.g., gamma, white point and data remappings)used by corresponding control circuitry (e.g., timing controller anddata lines driver, not shown here, see FIG. 7). Each display apparatus(e.g., 1000) includes a display panel 100 that has a plurality of pixelsprovided thereon, with each pixel being independently drivable by arespective pixel drive signal, for example, a pixel electrode drivevoltage. Each pixel may have a corresponding color filter (not shown)disposed thereon such that the optical output of the individual pixel isdependent on the idiosyncrasies of its respective filter materials.During mass production, the characteristics of filter materials (e.g.,including optical transmittance and degree of wavelength filtering) mayvary due to changes of supply source, temperature, solvent mixings, etc.Thus it may not be known until actual measurements are taken, whatcompensating adjustments (e.g., image data value remappings) need to bemade for achieving desired luminances across all grayscale values (e.g.,0-255) and for achieving desired color purities and/or white pointtemperatures.

The luminance and color measuring part 600 of FIG. 1 is disposed asspaced apart from a corresponding display area (DA) of the display panelunder test 100 and in accordance with a predetermined, trapezoidal lightintake volume (where the setup could include an opaque light shieldencasing and defining the trapezoidal intake volume). The combination ofmeasuring part 600 (a.k.a. camera 600) and intake volume are used toobtain measurements of one or more of luminance values and color purity(e.g., spectrum distribution) values of the images displayed by thedisplay apparatus 1000. For example, the luminance and color measuringpart 600 may be a camera that includes a focusing and magnification lens(optionally adjustable), one or more (and optionally selectable)wavelength filters and a light detecting sensor matrix (e.g., a CCDcharge coupled one, not shown) responsive to light rays passed throughthe focusing lens, through one or more of the selectable wavelengthfilters, where the light rays may have respective angles of travel fromcorresponding light source points on the display area of the displaypanel 100 to counter-corresponding light detection points on the lightdetecting sensor matrix. The light detecting sensor matrix (e.g., CCD,not shown) is, or is coupled to a serial information communicatingelement (e.g., serial digital data) and as such it requires a minimumpredetermined amount of time per photons capturing area on its face tocommunicate the collected photons information. The more suchindividualized photon capturing areas (e.g., sensor pixels) there are,the longer it takes for the camera 600 to serially communicate all itstaken measurements to the data receiving external unit (e.g., computer700). In one embodiment, it takes about 300 ms (milliseconds) toserially communicate all the measurements of a so-called, “full screen”exposure. In the optional case where the camera 600 has adjustablefocusing, adjustable aperture and/or adjustable magnification factorlens, it may take additional time to adjust these for each of successiveexposures. Moreover, it takes a finite amount of time for the measuringpart 600 to collect a sufficient intake of photons during eachrespective exposure (while its electrically controlled shutter is open).In one embodiment, it takes about 200 ms (milliseconds) per exposure.(In one variation, less exposure time is needed for brighter grayscalevalues. In another variation, a same amount of minimum exposure time isneeded irrespective of grayscale value.) Thus, assuming a fixed 200 msfor each exposure and a fixed 300 ms to output the full screen results,it takes about 500 milliseconds for taking each snapshot (assuming noadditional time is consumed for optional adjustments). Accordingly, whenplural snapshots are required (e.g., a minimum of 25 full screensamples) for completing a high precision calibration process, a largeamount of time may be consumed for appropriate measurements taking,serially reporting out the measurements and for appropriatelycalibrating each of a plurality of mass produced display apparatuses999, 1000, 1001 on the basis of their respective measurements taking andreporting operations.

In one embodiment, the luminance and color measuring part 600 is fixedlydisposed to have a central focus line corresponding to a central portionof the display panel 100 and an adjustable measurements reportingparameter that determines how much of a centrally disposed area of thecamera's sensor array (e.g., CCD array) will report out its results byway of serial communication. If the full area of the sensor array (e.g.,CCD array) reports out that takes a first predetermined amount of time.On the other hand, if a smaller (less than full) area of the sensorarray reports out that takes a second predetermined amount of time whichis less than the first predetermined amount of time. The data processingunit (e.g., computer 700) may be configured to alter the address rangesof the sensor pixels that report out their results (e.g., via a seriallink) and/or to alter the exposure duration (e.g., shutter open time) ofeach exposure.

In other words, the luminance and color measuring part 600 may consume afirst amount of time to output first measurement signals correspondingto the luminance and colors of the entire display area (DA) of thedisplay panel 100 when a so-called, “full screen” exposure is commandedby the data processing unit 700. On the other hand, the luminance andcolor measuring part 600 may consume a second and shorter amount of timeto output second measurement signals corresponding to the luminance andcolors of only a portion of the entire display area (DA) of the displaypanel 100 when a so-called, “partial screen” exposure is commanded bythe data processing unit 700 and/or when a shorter exposure duration iscommanded. In one embodiment, when a “partial screen” exposure iscommanded, the luminance and color measuring part 600 outputs its secondmeasurement signals as corresponding to the luminance and colors of aspecific pre-specified one or more subsections of the entire displayarea (DA), for example of only a central subportion of the display panel100 having a predetermined size that is subdivided into predeterminedand equal area subsections (e.g., in the below described “multi-pattern”mode).

As part of the sped-up calibration process disclosed here, the displaypanel 100 is selectively driven to display a so-called, “full” patternimage. The “full” pattern image is one that drives all the pixels of thedisplay area (DA) in a same one way, for example by applying a samepixel electrode drive voltage to all the pixels. The luminance and colormeasuring part 600 captures the full pattern image and correspondinglyreports out to the data processing unit 700 all of the sensed luminancesand color points (e.g., in CIE 1931 space) of the full pattern image(step S100). In other words, the full pattern image is a sample imagewhich is produced using a single grayscale value for driving all thepixels (where in one case, each pixel is understood to include primarycolor subpixels such as Red, Green and Blue such that the pixels canproduce a corresponding shade of white light). In the presentspecification, the single driving grayscale signal of the full patternimage and its capture is referred to as a “full” grayscale exposure run.

More specifically, by using different and respective, single drivinggrayscale signals, the display panel 100 may be caused to display aplurality of different “full” patterns. The luminance and colormeasuring part 600 may receive the corresponding full pattern images foreach of these grayscale drive values and may determine the respectivefull screen luminance and full screen color attributes of the respectivebut different full pattern images. On the other hand, by limiting thenumber of different full pattern images used (e.g., by not displayingall possible grayscale values as full screen images) and by usingvarious interpolation techniques to interpolate for the expected valuesof most or all other such full pattern images across the full grayscalevalues range (e.g., 0-255) of the display apparatus 1000, it is possibleto reduce the time consumed by the calibration process. In oneembodiment, less than 25 full screen exposures are taken and inaddition, one or a few partial screen/multi-gray exposures are taken.The partial screen/multi-gray exposures consume less time for exposureand/or out-reporting than do their corresponding full screen exposuresand thus the overall time for measurements taking can be advantageouslyreduced. In one embodiment, when a partial screen/multi-gray exposure isused, the read-outs from its respective and different grayscale valueareas are converted into virtualized full screen images by way of avirtualization process that includes the steps of virtuallyrepositioning the sensed grayscale value area to a central position ofthe full screen and virtually expanding the repositioned image to fillthe full screen area while mimicking camera and panel distortionattributes such that the generated, virtualized full screen imageclosely approximates what an actual full screen image for that grayscalevalue would have looked like.

FIG. 3A represents a driving of the display panel 100 with a first fullpattern image signal F1 corresponding to a first full grayscale valueGF1. FIG. 3B represents a driving of the display panel 100 with adifferent second full pattern image signal F2 corresponding to a secondfull grayscale value GF2. FIG. 3C represents a driving of the displaypanel 100 with a different third full pattern image signal F3corresponding to a third full grayscale value GF3.

For example, the first full grayscale GF1 may be a near-black grayscalerepresenting a substantially black but not totally black image. Forexample, given a range of 0 to 225, the first full grayscale value GF1may have a value of about four (4) in such a 0-255 grayscales range.

The second full grayscale value GF2 may be a medium grayscale valuerepresenting an image of intermediate brightness between the near-blackimage and a white or near-white further image. For example, the secondfull grayscale value GF2 may be closer to the near black grayscale valuethan to a fully-white grayscale. For example, the second full grayscaleGF2 may have a value of about 64 in such a grayscales range (0-255).

The third full grayscale GF3 may be the maximum whiteness drive signalrepresenting the fully white image. For example, the third fullgrayscale GF3 may have a value of 255 in such a grayscales range(0-255).

It has been empirically found that for good accuracy; at least 25 suchdifferent and full screen exposures should be taken. However, inaccordance with one embodiment of the present disclosure, just theaforementioned three full screen exposures are taken and at least onepartial screen exposure (FIG. 3D, described shortly below) is taken.Although, in this given example the display panel 100 is caused todisplay just three full screen images GF1, GF2 and GF3, the presentinventive concept is not limited thereto and the display panel 100 maybe caused to automatically display a slightly larger number of suchdifferent but full screen exposure images (say four to six) with theunderstanding that an object of the present teachings is to reduce timeconsumed per display device (999, 1000, 1001) for measurements takingand for subsequent generating of its compensation parameters (e.g.,compensating for deviation in luminance from desired output levels, fornonuniformity of luminance across the full screen and/or fornonuniformity of color across the full screen and/or for nonuniformityof side-view visibility across the full screen).

In addition to causing the display panel 100 to display just a smallnumber (e.g., 3 to 6) of different full screen images (GF1-GFn), inorder to calibrate the display panel 100 in accordance with the presentteachings, the display panel 100 is caused to display at least onesmaller-area, “multi” pattern image as driven by a corresponding atleast one multi-pattern image signal M1 (FIG. 3D). The rest of thedisplay area may be driven full black or otherwise. When the partialscreen mode (e.g., FIG. 3D) is in effect, the luminance and colormeasuring part 600 is controlled by the data processing unit 700 tofocus report-out just the sensor array readings for the smaller area ofthe partial screen. Accordingly, less time is consumed for reporting outonly the sensor readings of the partial screen. The data processing unit700 receives the output sensor readings of the multi pattern image anduses them in combination with interpolation techniques to determinecorresponding further luminances and corresponding color coordinatevalues expected of full screen versions of the actually measured, butsmaller area grayscale regions of the multi pattern image. Themeasurements taking operations of the exemplary four exposures of FIGS.3A-3D is referred to in the flowchart of FIG. 2 as a fewer exposures andsmaller report-out step (S100). Each multi pattern image (e.g., FIG. 3D)is a sample image which has a plurality of different grayscales. Inaccordance with one optional but not necessary aspect of the presentdisclosure, the multi pattern image covers substantially less than thefull display area (DA). However, as will be understood, it is possibleto attain some of the advantages of the present teachings even if themulti pattern image is a full screen one so long as different grayscalevalues are included within the multi pattern image, where these arecalled multi grayscales.

In one embodiment, a 25 full screen exposures test where the respectivegrayscale values are: GS=0, 3, 5, 8, 10, 15, 20, 25, 30, 35, 40, 50, 60,70, 80, 90, 100, 110, 130, 150, 170, 190, 210, 230, 255 in the case ofthe full grayscale values range being 0-25. In place of those 25 fullscreen exposures, in one embodiment, only 9 full screen exposures aretaken having respective and different grayscale values of GS=0, 8, 20,35, 60, 90, 130, 190 and 255. In addition, two “multi-pattern” modeexposures of partial screen size are taken (e.g., FIGS. 4A-4B) havingrespective and different grayscale values of GS=3, 5, 10, 15, 20, 25,30, 40 and 50 for the so-called, darker “multi-pattern” mode exposure(e.g., FIG. 4A) and having respective and different grayscale values ofGS=70, 80, 100, 110, 130, 150, 170, 210 and 230 for the so-called,brighter “multi-pattern” mode exposure (e.g., FIG. 4B). It may be notedthat in this given example, the grayscale value of GS=20 appears as oneof the full screen exposures and also as a repeated grayscale valueinside the darker “multi-pattern” mode exposure. Similarly, thegrayscale value of GS=130 appears as one of the full screen exposuresand also as a repeated grayscale value inside the brighter“multi-pattern” mode exposure. These few, repeated grayscale values maybe used as anchor points for cross correlating (e.g., normalizing) asbetween the results of the full screen exposures and the results of the“multi-pattern” mode exposures. (Each of the darker and brightermulti-pattern exposures has 8 grayscale values different from any of the9 full screen exposures. Therefore the total number of differentgrayscale values used for measurements taking is 9+8+8 which correspondsto 25 different grayscale values.

More specifically, as another example and in addition to the respectivethree full screen exposures of FIGS. 3A-3C, the display panel 100 may becaused to display just one multi pattern image presenting 9 differentgrayscale values GS=GM1, GM2, . . . , GM9 and occupying only a centralportion of the display area (DA) as illustrated in FIG. 3D.Alternatively, the display panel 100 may be caused to display a greaterbut nonetheless relatively small number rather than just one of suchmulti pattern images (say two or three) with the understanding that anobject of the present teachings is to reduce time consumed per displayfor number of exposures taken and amount of time consumed reporting outto the data processing unit 700 the readings of each exposure. The dataprocessing unit 700 verifies that the reported out readings are in goodorder and then the under test display device (e.g., 1000) may be movedaway from the camera 600 so a next in line display device (e.g., 1001)can take its place. The data processing unit 700 may continue to remainin contact with the moved away first display device (e.g., 1000) and maygenerate its respective compensation parameters (those for device 1000)and program them into that device (e.g., 1000) after it has move away.At the same time, the data processing unit 700 may handle the exposuresprocess for the next in line display device (e.g., 1001). Therefore, thespeed of the mass production line is improved.

As a different example, the case may be that the display panel 100instead displays two multi pattern images, where a first of these multipattern images includes relatively low multi grayscales that require acomparatively longer exposure time while the second multi pattern imageincludes relatively higher multi grayscales which in one embodiment,require a comparatively shorter exposure time when poising in front ofcamera 600. In the latter case, a shorter exposure time is used for therelatively higher multi grayscales and as a result, time consumed formeasurements taking is advantageously reduced.

FIG. 3D represents the first multi pattern image M1. For example, afirst multi grayscale value (different from those of FIGS. 3A-3C) may bedisplayed as a first multi pattern image GM1 disposed at an upper leftcorner of the partial screen pattern M1. At the same time, a fifth multigrayscale value (which is repeat of one of those of FIGS. 3A-3C) may bedisplayed as a fifth multi pattern image GM5 disposed a central portionof the partial screen image M1. More specifically, the multi grayscalespattern of FIG. 3D may be displayed in the form of a predeterminedchecker board pattern whose rectangles are of equal size but containdifferent grayscale values, for example brighter rectangles alternatingwith darker rectangles. For example, the first multi pattern image M1includes first to ninth multi grayscales GM1 to GM9.

Although, the exemplary first multi pattern image M1 includes just ninemulti grayscales GM1 to GM9 in the present exemplary embodiment, thepresent disclosure of inventive concept(s) is not limited thereto andthe so-called, “multi-pattern” mode images may contain other numbers ofdifferent grayscale values, for example, 12 or 16 (corresponding to a3×4 array and a 4×4 array respectively).

The multi grayscale region of the display panel 100 represents variousluminances and colors due to uniformity of a backlight assembly anduniformity of pixels of the display panel 100 and it also represents aspecific viewing angle (e.g., central and head on) according to aposition of the first multi pattern image M1 within the larger displayarea (DA) of the display panel 100.

Thus, when the display panel 100 is compensated based on measured valuesof the multi grayscale region of the first multi pattern image M1 aswell as the different full pattern images (GF1-GFn), the luminance andthe color of the display panel 100 may be more accurately compensatedfor by use of interpolation and normalization as compared to when justthe central multi pattern image M1 is used or just the full patternimages (GF1-GFn) are used.

In accordance with the present disclosure, a first compensating value isgenerated corresponding to displacing respective positions of thecentralized multi grayscales in the multi grayscale region to offcentral portions by way of software processing (for example by way ofnormalization, interpolation and/or superposition based on thenon-displayed pattern that can be predicted based on the measurementstaking obtained using the first multi pattern image M1 and the handfulof full pattern images (GF1-GFn). After software is used to predictivelygenerate virtual full screen results for the grayscale values for whichfull screen measurements were not actually taken, the rest of theprocessing may complete as in previous systems (e.g., the ones thatconsume more time by taking 25 or more full screen exposures). Thepredictive process may include a uniformity and viewing angle predictingstep (step S200) that takes into account how uniformity and viewingangle change in the sensor readings obtained from the full screenexposures. The predictive process may include a partial screen versusfull screen predicting step (step S300) that takes into account howresults may change due to measurements taking and readout occurring onlyfrom a smaller section of the sensor array rather than its whole area.

When a first compensating value (e.g., determined by normalizationand/or interpolation) is added to the measured value of the multigrayscale, the added value may represent the multi grayscale at thecentral portion GM5 of the first multi pattern image M1.

One embodiment of the first image compensation step S200 may beexplained in more detail by referring to the example of FIGS. 4A to 4Cin detail.

A measured value of the grayscale in the multi pattern image, which iscalled as a local pattern measured value, may be different from ameasured value of the corresponding grayscale in the full pattern image,which is called as a full pattern measured value, for the same grayscale(the repeated grayscale value, e.g., that of GM5) due to a reflectivityidiosyncrasy (e.g., refractive aberration) of a lens of the luminanceand color measuring part 600, where the latter is a characteristic of amodulation transfer function of the luminance and color measuring part600. The deviation may alternatively or additionally be due to crosstalkwithout the optical sensor array of the luminance and color measuringpart 600.

Thus, when the display panel 100 is compensated based on a measuredvalue at the multi grayscale region of the first multi pattern image M1,the luminance and the color of the display panel 100 may not beaccurately compensated for so as to consider deviations due torefractive aberration and/or sensor cross talk.

A second compensating value is generated to compensate for a measureddifference between the full pattern measured value and the local patternmeasured value (step S300).

When the measured value of the multi grayscale is multiplied by thesecond compensating value, the multi grayscale value in the localpattern may be converted to the multi grayscale value in the full pattervalue.

The second image compensation step S300 is explained referring to FIGS.5A and 5B in detail.

Although the second measurements taking compensating step S300 isoperated after the first measurements taking compensating step S200 inthe present exemplary embodiment, the present teachings are not limitedto this sequence of the first and second measurements takingcompensating steps S200 and S300. Alternatively, the first measurementstaking compensating step S200 may be carried out after the secondmeasurements taking compensating step S300.

The luminance and the color of the display panel 100 are compensatedbased on the luminances and the colors of the first full pattern imagesignals F1, F2 and F3, the luminance and the color of the first multipattern image M1, the first compensating value and the secondcompensating value (step S400).

FIGS. 4A to 4C are conceptual diagram illustrating the firstmeasurements taking compensation step S200 of FIG. 2.

Referring to FIGS. 1 and 4A to 4C, in the present exemplary embodiment,a measured value of a sixth multi grayscale GM6 at a second position P2in FIG. 4C is converted to a predicted value at a first position P1which is a central portion of the first multi pattern image M1 by use ofthe calculated first compensating value. (Stated otherwise, a predictiveextrapolation factor is found that predicts variation based on steppingaway from position P2 to the central position P1 in the case of FIG. 4Cand the case of the P2 grayscale value.)

FIG. 4A represents a low full image LF having a low full grayscale whichis one of the full grayscales less than the sixth multi grayscale GM6and adjacent to the sixth multi grayscale GM6. In the present exemplaryembodiment, the low full image LF may be substantially the same as thesecond full pattern image F2 in FIG. 3B.

FIG. 4B represents a high brightness full image HF having a high fullgrayscale which is one of the full grayscales greater than the sixthmulti grayscale GM6 and adjacent to the sixth multi grayscale GM6. Inthe present exemplary embodiment, the high full image HF may besubstantially the same as the third full pattern image F3 in FIG. 3C.

For example, when the multi grayscale of the first multi pattern imageM1 is between the first full grayscale GF1 and the second full grayscaleGF2, the low full image LF may be the first full pattern image GF1 andthe high full image HF may be the second full pattern image GF2.

For example, when the multi grayscale of the first multi pattern imageM1 is between the second full grayscale GF2 and the third full grayscaleGF3, the low full image LF may be the second full pattern image GF2 andthe high full image HF may be the third full pattern image GF3.

The first compensating value may be generated using the high full imageHF having the high full grayscale HF and the low full image LF havingthe low full grayscale LF.

For example, to convert the measured value of the sixth multi grayscaleGM6 at the off-center second position P2 in FIG. 4C to the value of thesixth multi grayscale GM6 at the central first position P1, a lowgrayscale difference between a measured value of the low full grayscaleat the first position P1 in the low full image LF in FIG. 4A and ameasured value of the low full grayscale at the second position P2 inthe low full image LF in FIG. 4A is determined. In addition, to convertthe measured value of the sixth multi grayscale GM6 at the secondposition P2 in FIG. 4C to the value of the sixth multi grayscale GM6 atthe first position P1, a high grayscale difference between a measuredvalue of the high full grayscale at the first position P1 in the highfull image HF in FIG. 4B and a measured value of the high full grayscaleat the second position P2 in the high full image HF in FIG. 4B isdetermined.

The high grayscale difference and the low grayscale difference may belinearly interpolated using the high full grayscale (e.g. 255grayscales), the sixth multi grayscale GM6 and the low full grayscale(e.g. 64th shade in the grayscales range) to determine the firstcompensating value.

A process of converting the measured value of the sixth multi grayscaleGM6 at the second position P2 to the value of the sixth multi grayscaleGM6 at the first position P1 may be explained referring to followingEquations 1 to 5.

In Equations 1 to 5, the low full grayscale is LG, the measured value ofthe low full image LF at the first position P1 is LG1, the measuredvalue of the low full image LF at the second position P2 is LG2, the lowgrayscale difference is dLG, the high full grayscale is HG, the measuredvalue of the high full image HF at the first position P1 is HG1, themeasured value of the high full image HF at the second position P2 isHG2, the high grayscale difference is dHG, the measured value of themulti grayscale at the second position P2 is XG, a converting ratio isGR, the first compensating value is C1(XG), the converted value of themulti grayscale at the first position P1 is CXG.dLG=LG1−LG2  [Equation 1]:dHG=HG1−HG2  [Equation 2]:GR=(XG−LG)/(HG−LG)  [Equation 3]:C1(XG)=GR(dHG−dLG)  [Equation 4]:CXG=XG+C1(XG)  [Equation 5]:

FIGS. 5A and 5B are conceptual diagram illustrating the second imagecompensation step S300 of FIG. 2;

Referring to FIGS. 1 and 5A to 5B, the first multi pattern image M1includes a common multi grayscale which is the substantially same as oneof the full grayscales GF1, GF2 and GF3 of the full pattern images F1,F2 and F3.

In the present exemplary embodiment, a third multi grayscale GM3 of thefirst multi pattern image M1 may be the substantially same as the secondfull grayscale GF2 of the second full pattern image F2. Thus, the thirdmulti grayscale GM3 of the first multi pattern image M1 may be thecommon multi grayscale.

The second compensating value is generated using a ratio between themeasured value of the second full grayscale GF2 which is substantiallythe same as the common multi grayscale GM3 and the measured value of thecommon multi grayscale GM3 in the first multi pattern image M1.

A measured position of the measured value of the second full grayscaleGF2 which is substantially the same as the common multi grayscale GM3may be the same as a measured position of the measured value of thecommon multi grayscale GM3 in the first multi pattern image M1.

The position of the common multi grayscale GM3 in the first multipattern image M1 is a third position P3. Thus, the common multigrayscale GM3 in the first multi pattern image M1 is measured at thethird position P3.

To generate the second compensating value, the second full grayscale GF2which is substantially the same as the common multi grayscale GM3 may bemeasured at the third position P3 in the second full pattern image F2.

Alternatively, the measured value of the common multi grayscale GM3 atthe third position P3 in the first multi pattern image M1 may beconverted the value of the common multi grayscale GM3 at the firstposition P1 by the first measurements taking compensation step S200.Then, to generate the second compensating value, the second fullgrayscale GF2 which is substantially the same as the common multigrayscale GM3 may be measured at the first position P1 in the secondfull pattern image F2.

When all the multi grayscales in the first multi pattern image M1 aremultiplied by the second compensating value, the local pattern measuredvalues measured at the local pattern may be converted to a predicted(virtual) full pattern of measured values as if measured at the fullpattern even though they were not.

FIG. 6A is a graph illustrating the gamma value by the imagecompensation of the display panel 100 of FIG. 1. FIG. 6B is a graphillustrating the color coordinate by the image compensation of thedisplay panel 100 of FIG. 1.

Referring to FIGS. 1 to 6B, the luminances and the color coordinates maybe substantially uniform according to the grayscales by the method ofcompensating the image of the display panel 100.

In FIG. 6A, the gamma values of the display panel 100 may besubstantially uniform except for those of grayscale values that are lessthan GS=30 (in the exemplary range of 0-255 grayscales). The gamma valueof the display panel 100 may be about 2.2.

In FIG. 6B, the color coordinates of the display panel 100 may besubstantially uniform except for those of grayscale values that are lessthan GS=30 (in the exemplary range of 0-255 grayscales). An x coordinateof the color coordinate (1931 CIE standard) of the display panel 100 maybe about 0.26. A y coordinate of the color coordinate of the displaypanel 100 may be about 0.28.

According to the present exemplary embodiment, the luminance and thecolor are compensated using the full pattern image and the multi patternimage so that time for measurements taking for the display panel 100 maybe dramatically decreased.

In addition, the difference between measured values according to theposition in the multi grayscale region and the difference between thefull pattern measured value and the local pattern measured value arecompensated for so that the luminance and the color of the display panel100 may be accurately compensated for.

Therefore, the gamma values and the color coordinates may be compensatedfor all of the display panels in a mass production batch so thatreliability of each display apparatus in the mass-produced batch may bedramatically improved.

FIG. 7 is a block diagram illustrating a display apparatus that may beused in the above described methods of driving the display panel 100while posing in front of the camera 600 (which drive method can furtherinclude the method of compensating the “multi-pattern” mode images so asto generate virtualized full screen measurements in accordance with FIG.2).

Referring to FIGS. 1 to 7, the display apparatus includes a displaypanel 100 and a panel driver. The panel driver includes a timingcontroller 200, a gate lines driver 300, a gamma reference voltagegenerator 400 and a data lines driver 500.

The display panel 100 has a display region (DA) on which an image isdisplayed and a non-displaying peripheral region adjacent to the displayregion.

The display panel 100 includes a plurality of gate lines GL, a pluralityof data lines DL and a plurality of unit pixels connected to the gatelines GL and the data lines DL. The gate lines GL extend in a firstdirection D1 and the data lines DL extend in a second direction D2crossing the first direction D1.

Each unit pixel includes a switching element (not shown), a liquidcrystal capacitor (not shown) and a storage capacitor (not shown). Theliquid crystal capacitor and the storage capacitor are electricallyconnected to the switching element. The unit pixels may be disposed in amatrix form.

The timing controller 200 receives input image data RGB and an inputcontrol signal CONT from an external apparatus (not shown). The inputimage data may include red image data R, green image data G and blueimage data B. The input control signal CONT may include a master clocksignal and a data enable signal. The input control signal CONT mayinclude a vertical synchronizing signal and a horizontal synchronizingsignal.

The timing controller 200 generates a first control signal CONT1, asecond control signal CONT2, a third control signal CONT3 and a datasignal DATA based on the input image data RGB and the input controlsignal CONT.

The timing controller 200 generates the first control signal CONT1 forcontrolling an operation of the gate lines driver 300 based on the inputcontrol signal CONT, and outputs the first control signal CONT1 to thegate lines driver 300. The first control signal CONT1 may furtherinclude a vertical start signal and a gate clock signal.

The timing controller 200 generates the second control signal CONT2 forcontrolling an operation of the data lines driver 500 based on the inputcontrol signal CONT, and outputs the second control signal CONT2 to thedata lines driver 500. The second control signal CONT2 may include ahorizontal start signal and a load signal.

The timing controller 200 generates the data signal DATA based on theinput image data RGB. The timing controller 200 may be programmablyconfigured (calibrated) to counter-compensate for luminance and coloridiosyncrasies of the display panel 100 by adding compensating values tothe input image data RGB based on luminance and the color compensationsderived from the measurements taking using the full pattern images F1,F2 and F3 (each of which includes a single full grayscale GF1, GF2 andGF3) and using the multi pattern image M1 which includes a plurality ofmulti grayscales GM1 to GM9. Virtualization of the partial screensamples of the “multi-pattern” image M1 into corresponding, but virtualfull screen pattern may make use a first compensating value whichaccounts for displacing the position of the multi grayscale portions GM1to GM9 in the multi pattern image M1 to the central portion of the multipattern image M1 and of a second compensating value which accounts forthe difference of the full pattern measured values and the local patternmeasured values. The timing controller 200 outputs the calibrated datasignal DATA to the data driver 500.

The timing controller 200 generates the third control signal CONT3 forcontrolling an operation of the gamma reference voltage generator 400based on the input control signal CONT, and outputs the third controlsignal CONT3 to the gamma reference voltage generator 400.

The gate lines driver 300 generates gate signals driving the gate linesGL in response to the first control signal CONT1 received from thetiming controller 200. The gate lines driver 300 sequentially outputsthe gate signals to the gate lines GL.

The gate lines driver 300 may be directly mounted on the display panel100, or may be connected to the display panel 100 as a tape carrierpackage (“TCP”) type. Alternatively, the gate lines driver 300 may bemonolithically integrated on the display panel 100.

The gamma reference voltage generator 400 generates a gamma referencevoltage VGREF in response to the third control signal CONT3 receivedfrom the timing controller 200. The gamma reference voltage generator400 provides the gamma reference voltage VGREF to the data driver 500.The gamma reference voltage VGREF has a value corresponding to a levelof the data signal DATA.

In an exemplary embodiment, the gamma reference voltage generator 400may be disposed in the timing controller 200, or in the data driver 500.

The data lines driver 500 receives the second control signal CONT2 andthe data signal DATA from the timing controller 200, and receives thegamma reference voltages VGREF from the gamma reference voltagegenerator 400. The data driver 500 converts the data signal DATA intodata voltages having an analog type using the gamma reference voltagesVGREF. The data lines driver 500 outputs the data voltages to the datalines DL.

The data lines driver 500 may include a shift register (not shown), alatch (not shown), a signal processing part (not shown) and a bufferpart (not shown). The shift register outputs a latch pulse to the latch.The latch temporally stores the data signal DATA. The latch outputs thedata signal DATA to the signal processing part. The signal processingpart generates a data voltage having an analog type based on the datasignal having a digital type and the gamma reference voltage VGREF. Thesignal processing part outputs the data voltage to the buffer part. Thebuffer part compensates the data voltage to have a uniform level. Thebuffer part outputs the compensated data voltage to the data line DL.

The data lines driver 500 may be directly mounted on the display panel100, or be connected to the display panel 100 in a TCP type.Alternatively, the data lines driver 500 may be monolithicallyintegrated on the display panel 100.

According to the present inventive concept as explained above, the gammavalue and the color coordinate are compensated for using measurementtakings using just a few full pattern images and at least one multipattern image so that time for measurements taking may be decreased. Inaddition, error due to use of the multi pattern image in place of aplurality of full screen images is compensated for so that the gammavalue and the color coordinate of the image may be accuratelycompensated. Thus, reliability of the display panel may be improved.

The foregoing is illustrative of the present disclosure of inventiveconcept(s) and is not to be construed as limiting thereof. Although afew exemplary embodiments have been described, those skilled in the artwill readily appreciate in view of the foregoing that many modificationsare possible in the exemplary embodiments without materially departingfrom the novel approaches and advantages of the present teachings.Accordingly, all such modifications are intended to be included withinthe scope of the present disclosure. In the claims, means-plus-functionclauses are intended to cover the structures described herein asperforming the recited function and not only structural equivalents butalso equivalent structures.

What is claimed is:
 1. A machine implemented method of compensating animage of a display panel, the method comprising: capturing a pluralityof full pattern images corresponding to a plurality of full grayscales,each full pattern image being the image of an entire display area of thedisplay panel; measuring luminance and color of the plurality of fullpattern images, each of the full pattern images including a single fullgrayscale of the full gray scales; measuring luminance and color of amulti pattern image, the multi pattern image including a plurality ofmulti grayscales; generating a first compensating value to displace aposition of a multi grayscale region in the multi pattern image to acentral portion of the multi pattern image; and compensating luminanceand color of the display panel based on the luminance and the color ofthe full pattern image, the luminance and the color of the multi patternimage and the first compensating value, wherein the first compensatingvalue is generated based on measurements taken from a high full imageand a low full image, the high full image having a high full grayscalewhich is one of the full grayscales greater than and adjacent to a multigrayscale of the multi grayscale region, the low full image having a lowfull grayscale which is one of the full grayscales less than andadjacent to the multi grayscale of the multi grayscale region, whereinthe generating of the first compensating value comprises: determining afirst difference between a measured value of the high full grayscale ata first position and a measured value of the high full grayscale at asecond position in the high full image and a second difference between ameasured value of the low full grayscale at the first position and ameasured value of the low full grayscale at the second position in thelow full image, the first position being the central portion of themulti pattern image, the second position being the position of the multigrayscale region; and linearly interpolating the first difference andthe second difference using the high full grayscale, the multi grayscaleof the multi grayscale region and the low full grayscale.
 2. The methodof claim 1, wherein the multi pattern image includes a common multigrayscale which is substantially the same as one of the full grayscales.3. The method of claim 2, further comprising generating a secondcompensating value using a ratio between a measured value of the fullgrayscale which is substantially the same as the common multi grayscaleand a measured value of the common multi grayscale in the multi patternimage.
 4. The method of claim 3, wherein a measured position of themeasured value of the full grayscale which is substantially the same asthe common multi grayscale is substantially the same as a measuredposition of the measured value of the common multi grayscale in themulti pattern image.
 5. The method of claim 1, wherein a number of thefull pattern images is greater than or equal to three.
 6. The method ofclaim 1, wherein a number of multi pattern images is two, and a firstmulti pattern image among the multi pattern images corresponds torelatively low grayscales and a second multi pattern image among themulti pattern images corresponds to relatively high grayscales.
 7. Amethod of compensating an image of a display panel, the methodcomprising: capturing a plurality of full pattern images correspondingto a plurality of full grayscales, each full pattern image being theimage of an entire display area of the display panel; measuringluminance and color of a plurality of full pattern images correspondingto a plurality of full grayscales, each of the full pattern imagesincluding a single full grayscale of the full grayscales; measuringluminance and color of a multi pattern image, the multi pattern imageincluding a plurality of multi grayscales; generating a firstcompensating value to displace a position of a multi grayscale region inthe multi pattern image to a central portion of the multi pattern image;compensating luminance and color of input image data based on the inputimage data, the luminance and the color of the full pattern image, theluminance and the color of the multi pattern image and the firstcompensating value to generate a data signal; and displaying an image onthe display panel based on the data signal, wherein the firstcompensating value is generated using a high full image and a low fullimage, the high full image having a high full grayscale which is one ofthe full grayscales greater than and adjacent to a multi grayscale ofthe multi grayscale region, the low full image having a low fullgrayscale which is one of the full grayscales less than and adjacent tothe multi grayscale of the multi grayscale region, wherein thegenerating of the first compensating value comprises: determining afirst difference between a measured value of the high full grayscale ata first position and a measured value of the high full grayscale at asecond position in the high full image and a second difference between ameasured value of the low full grayscale at the first position and ameasured value of the low full grayscale at the second position in thelow full image, the first position being the central portion of themulti pattern image, the second position being the position of the multigrayscale region; and linearly interpolating the first difference andthe second difference using the high full grayscale, the multi grayscaleof the multi grayscale region and the low full grayscale.
 8. The methodof claim 7, wherein the multi pattern image includes a common multigrayscale which is substantially the same as one of the full grayscales.9. The method of claim 8, further comprising generating a secondcompensating value using a ratio between a measured value of the fullgrayscale which is substantially the same as the common multi grayscaleand a measured value of the common multi grayscale in the multi patternimage.
 10. The method of claim 7, wherein a number of the full patternimages is greater than or equal to three.
 11. A display apparatuscomprising: a timing controller configured to compensate luminance andcolor of input image data to generate a data signal based on the inputimage data, luminance and color of a plurality of full pattern imagescorresponding to a plurality of full grayscales, luminance and color ofa multi pattern image and a first compensating value to displace aposition of a multi grayscale region in the multi pattern image to acentral portion of the multi pattern image, each of the full patternimages including a single full grayscale of the full grayscales, themulti pattern image including a plurality of multi grayscales; a datadriver configured to convert the data signal into a data voltage havingan analog type; and a display panel configured to display an image basedon the data voltage, wherein each full pattern image is a captured imageof an entire display area of the display panels, wherein the firstcompensating value is generated using a high full image and a low fullimage, the high full image having a high full grayscale which is one ofthe full grayscales greater than and adjacent to a multi grayscale ofthe multi grayscale region, the low full image having a low fullgrayscale which is one of the full grayscales less than and adjacent tothe multi grayscale of the multi grayscale region, wherein, to generatethe first compensating value, the timing controller is configured to:determine a first difference between a measured value of the high fullgrayscale at a first position and a measured value of the high fullgrayscale at a second position in the high full image and a seconddifference between a measured value of the low full grayscale at thefirst position and a measured value of the low full grayscale at thesecond position in the low full image, the first position being thecentral portion of the multi pattern image, the second position beingthe position of the multi grayscale region, and linearly interpolate thefirst difference and the second difference using the high fullgrayscale, the multi grayscale of the multi grayscale region and the lowfull grayscale.
 12. The display apparatus of claim 11, wherein the multipattern image includes a common multi grayscale which is substantiallythe same as one of the full grayscales.
 13. The display apparatus ofclaim 12, wherein the timing controller is further configured togenerate a second compensating value using a ratio between a measuredvalue of the full grayscale which is substantially the same as thecommon multi grayscale and a measured value of the common multigrayscale in the multi pattern image.
 14. The display apparatus of claim11, wherein a number of the full pattern images is greater than or equalto three.
 15. A machine implemented and automated method for quicklydetermining luminance and color compensation values for a display panelhaving a display area populated by a matrix of pixels, where each pixelis independently drivable over a predetermined range of grayscales, themethod comprising: first driving all the pixels with a first single fullgrayscale signal to thereby produce a corresponding first full screenimage and using a sensor array to measure luminance and color attributesof the produced first full screen image; second driving all the pixelswith a different second single full grayscale signal to thereby producea corresponding second full screen image and using the sensor array tomeasure luminance and color attributes of the produced second fullscreen image; third driving only a subset of the pixels of the displayarea with a corresponding multi pattern signal to thereby produce acorresponding multi pattern image having a predetermined spatialarrangement of darker and lighter regions and using the sensor array tomeasure respective luminances and color attributes of the respective andspatially arranged darker and lighter regions of the multi pattern imagecorresponding to only the subset of the pixels; using the measuredluminances and color attributes of the multi pattern image and of thefirst and second full screen images to generate luminance and colorcalibrating factors for the display panel.